What are the maximum and typical pressures ? - real life experience welcome ;-)

[77-1201624802]

Hi,

What are you day by day experiences with an orifice flow bench.
1. What size of heads do you generally test ?
a) ( cubic inch / cubic cm per cylinder)

1. Test-Pressure:
The "static" (test-pressure) is most times measured up to 28" h2o.
a) what is the maximum pressure you need to see at your flow bench ?
b) what is the average pressure you need the most of the time

2. Differencial Pressure across the orifice:
when you test a cylinder head what at the h2o rises in inch you need the most ?

a) what is the maximum pressure you suddenly see (too small / too large orifice for the test head) ?
b) what is the average pressure range when you do testings ?
(from xx inch to yy inch)


I hope many guys will answer their experience, as this helps (hopefully not only me) to get the right dimensions to buy / build the gauges.

Thanks,

Daniel

[larrycavan]

[77-1201624802]

Hi Larry,

Before you are pressing the "commercial-red-alarm-button", here my explanation: I am trying to find the (DIY,free for all ofcourse).

Since I have no running flow bench ready, I was asking around to not buy completly wrong dimensions.

And yes, I am in the state where I want to build my own flow bench, but I assume the flow bench ( for up to 400cc/24cuin cylinders with maximum of 50 hp per cylinder) will be complete after I already got the first digital display ready to go.

I really don't want to gather details for marketing, but for getting a good feeling what eventually could be interesting for all of us.

Cheers,

Daniel

[Tony]

Daniel, When building a manometer, either electronic or water, the bench design pressures can be whatever you decide they should be. But it really comes down to how much pressure your air blower can comfortably produce.

If your air blower is struggling for pressure, you may need to be content using a lower test pressure than 28 inches. There is nothing at all wrong with doing that.

Maximum possible overpressure is something else to think about. With your air blower running absolutely flat out, completely block the flow and see how high the pressure goes. It can sometimes be surprisingly high!

Both the bench itself, and the manometers must be able to survive the worst possible overpressure accident, without damage, because one day it is going to happen for certain.

[larrycavan]

[77-1201624802]

Hi Guys,


I am just back from vacation ( 6 days on a very small island, where no cars were allowed :O ). Nice time to chill out, eat much fish and get some energy back.

To Larry C:
Thanks for the hints. This helps me alot. for the test pressure I will start with 40 inch h2o.

To buy the first parts to play around, I just need the info how much pressure I have to work across the orifice. (The diagonal water gauge). What is the typical rise here ?

Cheers,

Daniel

PS: I will upload some photos of my new and tiny development kit soon.

[bruce]

Dp across the orifice plate can be anywhere from 6-28" depending on how someone builds a bench. I have found 10-12" gives a stable reading with water gages and the orifice hole sizes are not to large in the higher cfm range.

But, I'm not sure what is going to be the best Dp for a digital gage setup? This might have a lot to do with the sensitivity of the sensor being used? If you design for a range of Dp's it can be "custom tuned" for the bench maybe?

[77-1201624802]

Thanks.


I will buy a set of sensors and will play around with my development kit.

If anyone (whenever someone reads this) want to add his experiences, please post them. Everything else which is based on the digital meter should be in the .

Cheers,

Daniel

[106-1194218389]

I am using the Performance Trends Black box and have my Dp set to 12" (12" of rise on my inclined manometer) and it works very nice. My water gauge is also very steady. That is just what I use though.
John